[linux-dvb] Re: DVB and dual audio

["Robert Schlabbach" <robert_s@gmx.net>]

From: "Gerd Knorr" <kraxel@bytesex.org>
> Ondrej Zima <amiandrew@volny.cz> writes:
> > I have problem to select audio channel if the broadcast is in dual
> > languages. It plays from the left audio channel the native language
> > and from right the original language.
>
> Uh, thats a pretty strange way to broadcast dual-language ...

No, it's not. This has been provisioned in the MPEG audio standard right
from the start.

> Do you know how that differs from mono/stereo broadcast
> (i.e. how to detect this in the software)?

Check the "mode" bits in the MPEG audio header. They tell you whether the
audio is mono, dual channel, stereo or joint stereo. The "dual channel"
mode means that channel 1 and channel 2 carry separate audio and are NOT
the left and right channels of a stereo signal.

It's surprising that although this has been written in the MPEG audio
standard right from the start, hardly anyone has implemented this
correctly.

Regards,
--
Robert Schlabbach
e-mail: robert_s@gmx.net
Berlin, Germany